MXene‐Like Fe ₃ C–Mo ₂ C Hybrid Electrodes for High‐Performance Asymmetric Supercapacitors

In this study, an asymmetric hybrid supercapacitor based on transition metal carbides was designed and fabricated to enhance electrochemical energy storage performance. Molybdenum carbide (Mo ₂ C) and iron carbide (Fe ₃ C) were synthesized via chemical vapor deposition, enabling controlled thickness and well‐defined carbide architectures. Structural and morphological analyses confirmed uniform carbide growth, hierarchical surface features, and high crystallinity. A symmetric Mo ₂ C/Mo ₂ C device and several hybrid configurations were systematically constructed. In the optimized asymmetric hybrid design, Mo ₂ C served as the anode, while Fe ₃ C–Mo ₂ C acted as the cathode, resulting in enhanced conductivity, surface area, and charge storage capability. Electrochemical characterization revealed that the symmetric Mo ₂ C/Mo ₂ C supercapacitor delivered 30.68 mF at 1 V, whereas the Fe ₃ C–Mo ₂ C/Mo ₂ C asymmetric supercapacitor achieved 57.38 mF at 1 V and 75.10 mF at 2 V due to the synergistic hybrid architecture and expanded voltage window. Long‐term cycling tests demonstrated superior stability of the asymmetric hybrid device, retaining ∼97% of its initial capacitance over 10,000 cycles, compared to ∼65% for the symmetric Mo ₂ C/Mo ₂ C supercapacitor. These results demonstrate that hybrid asymmetric carbide electrodes are highly effective for advanced energy storage applications.